We propose that there is a subgroup of patients with PCOS who actually have non-CAH primary forms of BAH. To investigate this possibility, we propose to study the hypothalamic-pituitary-adrenal axis (HPAA) over the next 2 years in 120 young girls and women (ages 16 to 25 years) that we will compare to 30 age- and race-matched normal females. Patients will be recruited primarily (although not exclusively) from a busy New York City clinic run by the Pediatric Endocrine Division at the Infants and Children's Hospital of Brooklyn at Maimonides and SUNY Downstate. All patients will undergo standard testing of the HPAA including oral low- and high-dose dexamethasone (DEX)-suppression testing (Liddle s test). Paradoxical rise of cortisol and/or other steroid metabolites in response to DEX is considered a sensitive test for the diagnosis of BAH. Patients with such responses will be molecularly investigated for the known causes of BAH (GNAS, PRKAR1A, PDE11A, PDE8B and other mutations).